Idler guide unit

ABSTRACT

A taper-like block ( 26 ) slides on a slide plate ( 27 ) arranged on a track frame ( 11 ) by screwing an adjusting bolt ( 41 ). A bearing ( 21 ) moves to an upper side of the track frame ( 11 ) via rails ( 23, 24 ) fitted to a first inclined surface ( 26   a ) of the taper-like block ( 26 ). Accordingly, it is possible to adjust a gap (S 2 ) between a slide plate ( 31 ) on a hook portion ( 21   c ) of the bearing ( 21 ) and a slide plate ( 33 ) firmly fixed to a lower surface of the track frame ( 11 ).

TECHNICAL FIELD

The present invention relates to an idler guide apparatus in a crawler type traveling apparatus.

BACKGROUND ART

In a vehicle provided with a crawler type traveling apparatus such as a bulldozer, a hydraulic excavator and a crawler crane, a predetermined slack is provided in a crawler belt by generally setting a center distance between a drive side sprocket shaft and a driven side idler shaft. At an actual traveling time, for example, there is a case that sediment, rock or the like is pinched in an engagement portion between a sprocket and the crawler belt. At this time, a tensile force (hereinafter, refer to as a shoe tension) is generated all around the periphery of the crawler belt.

In order to protect the crawler type traveling apparatus from the generated shoe tension, the crawler type traveling apparatus is provided with an idler guide apparatus which supports an idler yoke rotatably bearing an idler so as to freely slide in a longitudinal direction of the crawler type traveling apparatus, and an idler cushion apparatus which absorbs an impulse force applied to the idler.

The idler cushion apparatus keeps the center distance between the idler shaft and the sprocket shaft in a state in which the shoe tension is equal to or less than a predetermined tension value, crushes the pinched sediment, rock or the like, and prevents an engagement displacement between the sprocket and the crawler belt (hereinafter, refer to as a crawler belt jump) and a crawler belt disengagement. Further, the configuration is made such that, when the shoe tension becomes a predetermined tension value or more, the apparatus retracts the idler to the sprocket side (hereinafter, refer to as recoil), and protects the crawler type traveling apparatus.

The idler cushion apparatus mentioned above is disclosed in a positioning apparatus of a grease fitting #manufactured by the applicant of the present invention (for example, refer to patent document 1), and conventionally has been in heavy usage with called as a spring box. An idler cushion apparatus 50 shown in FIG. 8 is an idler cushion apparatus described as a conventional art in the patent document 1, and is arranged within a track frame 82 of a crawler type traveling apparatus 89 as shown in FIG. 7.

As shown in FIG. 7, in the crawler type traveling apparatus 89, a sprocket 88 rotationally driven by a drive motor (not shown) is arranged in a rear end portion of the track frame 82, and a driven and rotating idler 91 is arranged in a front end portion of the track frame 82. A plurality of track rollers 86 are arranged in a lower portion of the track frame 82, and a plurality of carrier rollers 87 are arranged in an upper portion of the track frame 82. A crawler belt 84 is supported to the track rollers 86 and the carrier rollers 87, and is wound between the sprocket 88 and the idler 91.

As shown in FIG. 8, an idler guide apparatus 80 is attached to a front side of the idler cushion apparatus 50. The idler guide apparatus 80 is provided with a yoke unit 81 constituted by a yoke portion 81 a and a support portion 81 b, and the yoke unit 81 is arranged so as to be slidable on the track frame 82.

The idler cushion apparatus 50 is provided with an adjusting cylinder 52 comprising a piston rod 51 pressing into the yoke portion 81 a. The idler 83 is rotatably borne by the support portion 81 b.

The piston rod 51 is internally fitted to one side of the cylinder 52 having a flange 52 a in one side thereof, and a grease guide 55 having a grease passage in an inner portion of the grease guide is firmly fixed to the other end of the cylinder 52. The grease guide 55 is integrally formed with the cylinder 52.

One end side of a recoil spring 53 is brought into contact with the flange 52 a, and the other end side of the recoil spring 53 is brought into contact with a bottom 54 a of a cylindrical spring case 54 which becomes a cover of the recoil spring 53. A flange 54 b is provided in a portion in an opposite side to the bottom 54 a of the spring case 54, and a cover 56 which becomes a lid of the spring case 54 is attached thereto.

The bottom 54 a of the spring case 54 is slidably externally fitted to an outer periphery of the grease guide 55. A screw is provided in an end portion of the grease guide 55. It is possible to adjust a positional relationship between the spring case 54 and the grease guide 55 by engaging a nut 57 with the screw and fastening them. A grease fitting 58 is provided in an end surface of the grease guide 55.

A window 85 to which a grease gun is inserted is formed in the track frame 82. A faucet portion 54 c is formed in a leading end of the bottom 54 a, and the faucet portion 54 c is fitted to a hole 60 a of a support plate 60 firmly fitted perpendicularly to the track frame 82.

As the idler guide apparatus which slidably guides the yoke (corresponding to a yoke unit in the patent document 1 mentioned above), the yoke rotatably bearing the idler on the track frame, there is disclosed an idle wheel (which is also referred to as an idler, and is expressed as an idler in the following description) guide apparatus (refer to patent document 2). In FIG. 9, there is shown a configuration of an idler guide apparatus 90 in a conventional art described in the patent document 2.

In FIG. 9, the idler 91 is axially attached to an idler shaft 92 via a bush 93. A pair of bearings 94, each of which has a first slide plate 95 and a second slide plate 96, are arranged in both ends of the idler shaft 92, and are firmly fixed to the idler shaft 92 by bolts 97. The pair of bearings 94 rotatably bear the idler 91, and construct a part of the idler yoke.

A pair of track frames 105 are arranged in parallel in right and left sides of a vehicle, and an upper surface slide plate 106 is arranged on an upper surface of each of the pair of track frames 105. Further, a side surface guide plate 107 is welded to an outer side surface of each of the track frames 105. Both outer side surfaces of the side surface guide plate 107 are formed in parallel with an extending direction of the track frame 105. A bracket 108 is fixed by welding to each of both the inner side surfaces of the pair of track frames 105.

A lower surface slide plate 109 is welded to a lower surface of the bracket 108. The lower surface slide plate 109 faces via a gap S2 to the second slide plate 96 on a hook portion 102 formed in the bearing 94.

The first slide plate 95 of the bearing 94 is mounted on the upper surface slide plate 106 of the track frame 105, and mounts the idler 91 on the track frame 105 via the bearing 94.

Guide brackets 98 having guide surfaces 99 respectively are fastened to outer side surfaces of both the right and left bearings 94 via shims 100 by bolts 101. The guide surface 99 of the guide bracket 98 and the side surface guide plate 107 of the track frame 105 are adjusted by the shim 100 such that a slight gap S1 exists therebetween.

A yoke (the bearing 94 in the case of FIG. 9) bearing the idler 91 can slide on the upper slide plate 106 of the track frame 105 in a radial direction of the idler shaft 92. In the case that an upward force is applied to the idler 91 from a lower side in FIG. 9, the second slide plate 96 is brought into contact with the lower surface slide plate 109 provided in the bracket 108, thereby preventing the idler 91 from moving to an upper side. In the case that an external force in an axial direction of the idler shaft 92 is applied to the idler 91, the guide surface 99 of the guide bracket 98 is brought into contact with the side surface guide plate 107 so as to prevent a movement in an axial direction.

In the idler guide apparatus 90 described in the patent document 2, the idler 91 repeats a sliding motion together with the yoke (the bearing 94) during the vehicle's travel, and the first slide plate 95 of the bearing 94 and the upper surface slide plate 106 of the track frame 105 are worn away. At this time, the gap S2 between the second slide plate 96 of the bearing 94 and the lower surface slide plate 109 provided in the bracket 108 of the track frame 105 is enlarged.

Further, the downward force is not always applied to the idler 91, for example, when the crawler type traveling apparatus travels on a rough ground, there is generated a matter that the idler 91 is upthrown to the above by a concavity and convexity of the ground. In addition, when the vehicle moves backward, a tensile force is applied to the crawler belt traveling in an upper portion of the track frame 105, the crawler belt traveling in the upper portion is pulled by a backward rotation of the sprocket, and the idler is lifted to the upper side.

As a result, an upward force is applied to the idler 91 from a lower side in FIG. 9, a collision is generated between the second slide plate 96 and the lower surface slide plate 109 of the bracket 108, and the second slide plate 96 and the lower surface slide plate 109 are worn away.

In the crawler type traveling apparatus, in order to maintain a stability in the longitudinal direction of the vehicle with respect to a load applied to a working machine mounted on the vehicle, the idler and the sprocket are respectively operated as support points for maintaining the stability in the longitudinal direction. Accordingly, in general, as the idler guide apparatus, the abrasion of the guide member for regulating movement of the idler in a vertical direction is larger than the abrasion of the guide member for regulating movement of the idler in an axial direction of the idler shaft.

When the gap S2 between the second slide plate 96 of the bearing 94 and the lower slide plate 109 of the track frame 105 becomes larger due to the abrasion generated in the manner mentioned above, the bearing 94 and the track frame 105 come into collision with each other by moving along the gap S2.

Accordingly, a slapping sound is generated due to the collision between the bearing 94 and the track frame 105, and a traveling noise is increased. Further, there is generated a problem that a play is generated between the idle shaft 92 and the bearing 94, thereby triggering, for example, an oil leak of a lubricating oil injected between the idle shaft 92 and the bearing 94.

Any means for adjusting the gap in the idler guide apparatus is not provided in the crawler type traveling apparatus. Accordingly, the gap is kept in an increased state until the worn guide plate is replaced. As a result, the traveling noise of the crawler type traveling apparatus is loud.

-   -   patent document 1: microfilm of Japanese Utility Model         Application No. 4-41170 (Japanese Utility Model Application         Laid-Open No. 5-94078)     -   patent document 2: CD-ROM of Japanese Utility Model Application         No. 3-104649 (Japanese Utility Model Application Laid-Open No.         5-40090))

DISCLOSURE OF THE INVENTION PROBLEMS TO BE RESOLVED BY THE INVENTION

An object of the present invention is to solve the conventional problems mentioned above, and to provide an idler guide apparatus which easily adjusts a gap between a guide surface provided in a lower surface of a track frame and a guide portion of a bearing in an idler yoke, that is, a gap S2 between a lower surface slide plate provided in a lower surface of a track frame and a guide plate of the idler yoke facing to the lower surface slide plate, achieves a low traveling noise, and prevents an oil leak of a lubricating oil in the idler guide apparatus.

MEANS OF SOLVING THE PROBLEMS

The object of the present invention can be achieved by each of inventions described in first to fifth aspects of the present invention.

In other words, in accordance with a most main feature of the present invention, as described in a first aspect of the invention, there is provided an idler guide apparatus having a first guide surface and a second guide surface which are respectively provided in an upper surface and a lower surface of a track frame and form slide surfaces in a radial direction of an idler in a crawler type traveling apparatus, wherein an idler yoke rotatably bearing the idler is mounted on the first guide surface provided in the upper surface of the track frame, and an adjusting mechanism for adjusting a gap between the second guide surface provided in the lower surface of the track frame and a guide plate of the idler yoke facing to the second guide surface is formed in the idler yoke.

Further, in accordance with a main feature of the present invention, as described in a second aspect of the invention, the idler yoke is configured such as to have a taper-like block having a first inclined surface and an idler yoke slidably contacted by surface so as to lap over the first inclined surface, and an adjusting mechanism for sliding the taper-like block on the first guide surface and displacing the idler yoke in a perpendicular direction to the track frame is formed in the idler yoke.

Further, in accordance with a main feature of the present invention, as described in third to fifth aspects of the invention, actuating means for sliding the taper-like block on the first guide surface is provided in the adjusting mechanism.

EFFECT OF THE INVENTION

In accordance with the present invention, even if the gap between the second guide surface provided in the lower surface of the track frame and the guide plate of the idler yoke facing to the second guide surface is increased due to the abrasion, it is possible to easily adjust the gap by the adjusting mechanism formed in the idler yoke. Moreover, since the adjusting mechanism is formed in the idler yoke, it is possible to easily adjust the gap even in a working field in which the vehicle provided with the crawler type traveling apparatus works.

The adjusting mechanism for adjusting the gap may be constituted by the mechanism for sliding the taper-like block having the first inclined surface on the first guide surface provided on the upper surface of the track frame and displacing the idler yoke in the perpendicular direction to the track frame by utilizing the first inclined surface, as described in the second aspect. It is possible to easily lift up the idler having a great mass by the simple adjusting mechanism utilizing a wedge effect achieved by the first inclined surface of the taper-like block, whereby it is possible to easily adjust the gap.

The adjusting mechanism for adjusting the gap is not limited to the adjusting mechanism as described in the second aspect, but can be configured such that a guide moving member which can move close to and apart from the second guide surface is arranged in the guide plate of the idler yoke. It is possible to adjust the gap between the guide member and the second guide surface, by adjusting an approaching amount at which the guide moving member is moved close to the guide plate.

In addition, the adjusting mechanism can employ the other configurations as far as the configuration can adjust the gap.

In the case of using the taper-like block as described in the second aspect, it is possible to employ actuating means for sliding the taper-like block on the first guide surface. The actuating means can employ a configuration provided with an adjusting bolt pressing the taper-like block and a spring pressing the taper-like block to the adjusting bolt side, and a configuration using a cylinder apparatus in place of the adjusting bolt.

The position adjustment of the taper-like block using the adjusting bolt can be executed by manually rotating the adjusting bolt, or rotating the adjusting bolt by utilizing a drive motor or the like. In the case that a control motor is used as the drive motor, the slide position of the taper-like block can be adjusted on the basis of a remote control, for example, a remote control from a control compartment.

In the case of the actuating means using the cylinder apparatus, it is possible to employ a grease cylinder or a hydraulic cylinder utilizing a discharge pressure from a hydraulic pump, as the cylinder apparatus. In the case of using the hydraulic cylinder, the slide position of the taper-like block can be adjusted on the basis of the remote control.

It is easy to slide the taper-like block and position the taper-like block by using the actuating means, and the gap can be adjusted in response to the slide position of the taper-like block moved by the actuating means.

According to the present invention, even if the gap in the guide portion of the idler guide apparatus is increased due to the abrasion of the first guide surface and the second guide surface, the increased gap can be easily corrected. Moreover, the correction of the gap in the guide portion of the idler guide apparatus can be easily executed in the working field in which the vehicle works.

Accordingly, it is possible to provide an idler guide apparatus which can easily adjust a gap, can prevent a play between an idler shaft and a bearing and can lower a traveling noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a bulldozer having a crawler type traveling apparatus to which an idler guide apparatus and an idler cushion apparatus are applied (embodiment).

FIG. 2 is a detailed view of a portion P in FIG. 1 (first embodiment).

FIG. 3 is aback elevational view of across section along a line M-M in FIG. 2 (first embodiment).

FIG. 4 is a side elevational view of the idler guide apparatus before adjusting a gap (first embodiment).

FIG. 5 is a side elevational view of the idler guide apparatus after adjusting a gap (first embodiment).

FIG. 6 is a detailed view of a portion P in FIG. 1 in accordance with another embodiment (second embodiment).

FIG. 7 is a side elevational view of a crawler type traveling apparatus to which an idler guide apparatus is applied (conventional art).

FIG. 8 is a side elevational view of an assembled structure of the idler guide apparatus and an idler cushion apparatus (conventional art).

FIG. 9 is a cross sectional view of the idler guide apparatus (conventional art).

EXPLANATION OF REFERENCE LETTERS OR NUMERALS

 1 bulldozer  10 crawler type traveling apparatus  11 track frame  12 sprocket  13 idler  17 crawler belt  18 idler shaft  20 idler guide apparatus  21 bearing  21a, b flange portion  21c hook portion  23, 24 rail  23a, 24a groove  26 taper-like block  26a first inclined surface  27, 28 slide plate  30 idler yoke  30a second inclined surface  31 slide plate  32 bracket  33 slide plate  34 first guide surface  35 second guide surface  36 guide bracket  36a guide surface  39 guide plate  41 adjusting bolt  42 lock nut  43 spring  44 grease cylinder  45 piston  46 grease nipple  50 idler cushion apparatus  51 piston rod  52 cylinder  53 recoil spring  54 spring case  54a bottom  54b flange  54c faucet portion  55 grease guide  58 grease fitting  60 support plate  80 idler guide apparatus  81 yoke unit  81a yoke portion  81b support portion  82 track frame  83 idler  84 crawler belt  85 window  88 sprocket  89 crawler type traveling apparatus  90 idler guide apparatus  91 idler  92 idler shaft  94 bearing  95 first slide plate  96 second slide plate  98 guide bracket  99 guide surface 102 hook portion 105 track frame 106 upper surface slide plate 107 side surface guide plate 108 bracket 109 lower surface slide plate S1, S2, S2′ gap

BEST MODE FOR CARRYING OUT THE INVENTION

A description will be specifically given below of an idler guide apparatus according to a preferable embodiment of the present invention on the basis of the accompanying drawings by using an example that the idler guide apparatus is arranged in a crawler type traveling apparatus of a bulldozer. The idler guide apparatus of the present invention is not limited to the embodiments described below, but various configurations can be employed as far as it is possible to adjust a gap between a second guide surface 35 provided in a lower surface of a track frame and a guide plate of the idler yoke facing to the second guide surface 35.

First Embodiment

FIG. 1 is a side elevational view of a bulldozer 1 having a crawler type traveling apparatus 10 in which an idler guide apparatus 20 according to the present invention is arranged. The bulldozer 1 is provided with a long frame 2 extending in a longitudinal direction in a center portion thereof, and the crawler type traveling apparatus 10 is arranged in each of both right and left sides of the frame 2. A control compartment 3 or the like is mounted in an upper portion of the frame 2, and a working machine 4 is attached to a front portion of the frame 2.

An idler 13 is borne in a front end portion of a track frame 11 of the crawler type traveling apparatus 10 so as to be movable and rotatable in a longitudinal direction via an idler guide apparatus 20. The idler guide apparatus 20 is borne by an idler cushion apparatus 50, and has a buffering function with respect to an external force moving the idler 13 to a spool side and applied to the guide apparatus.

A sprocket 12 rotationally driven by a drive engine (not shown) is arranged in a rear end portion of the track frame 11 of the crawler type traveling apparatus 10. A crawler belt 17 is wound between the sprocket 12 and the idler 13. The crawler belt 17 traveling in a lower side of the track frame 11, that is, the crawler belt 17 traveling in a side contact with the ground surface in the crawler belt 17 wound between the sprocket 12 and the idler 13 is supported by a plurality of track rollers 15.

Further, the crawler belt 17 traveling in an upper side of the track frame 11, that is, the crawler belt 17 traveling in a side apart from the ground surface in the crawler belt 17 wound between the sprocket 12 and the idler 13 is supported by a carrier roller 16.

The idler guide apparatus 20 is attached to a front side of the idler cushion apparatus 50. The idler guide apparatus 20 is provided with a taper-like block 26 mounted on the track frame 11, and an idler yoke 30 mounted on the taper-like block 26. The idler yoke 30 and the taper-like block 26 can slide on the track frame 11 along a lateral direction in FIG. 1 on the basis of an actuation of a piston rod 51 of the idler cushion apparatus 50. The idler 13 is rotatably borne by the idler yoke 30.

As shown in FIGS. 4 and 5, the idler cushion apparatus 50 is provided with an adjusting cylinder 52 including a piston rod 51 which is brought into contact with the idler yoke 30. In this case, the configuration may be made such that the piston rod 51 and the idler yoke 30 are integrally operated, or the piston rod 51 is only brought into contact with the idler yoke 30.

The piston rod 51 is internally fitted to one side of the cylinder 52 having a flange 52 a in one side, and a grease guide 55 having a grease passage in an inner portion is firmly fixed to the other end of the cylinder 52. The grease guide 55 is integrally formed with the cylinder 52.

One end side of a recoil spring 53 is brought into contact with the flange 52 a, and the other end side of recoil spring 53 is brought into contact with a bottom 54 a of a cylindrical spring case 54 which becomes a cover of the recoil spring 53. A flange 54 b is provided in a portion of the spring case 54 in an opposite side to the bottom 54 a, and a cover 56 which becomes a lid of the spring case 54 is attached thereto.

The bottom 54 a of the spring case 54 is slidably externally fitted to an outer periphery of the grease guide 55. A screw is provided in an end portion of the grease guide 55. It is possible to adjust a positional relationship between the spring case 54 and the grease guide 55 by engaging a nut 57 with the screw and so as to fasten. A grease fitting 58 is provided in an end surface of the grease guide 55.

A window 85 to which a grease gun is inserted is formed in the track frame 11. A faucet portion 54 c is formed in a leading end of the bottom 54 a, and the faucet portion 54 c is fitted to a hole 60 a of a support plate 60 firmly fitted perpendicularly to the track frame 11.

In order to strengthen a tension of the crawler belt 17, it is preferable to enlarge a center distance between a sprocket (not shown) and the idler 13. For this purpose, the grease gun inserted from the window 85 is fitted to the grease fitting 58, and the grease is injected to the cylinder 52 via the grease guide 55. Accordingly, the piston rod 51 protrudes and the idler 83 is extruded, whereby the center distance can be enlarged.

In order to weaken the tension of the crawler belt 17, it is preferable to move the idler 13 to the sprocket side. For this purpose, the center distance can be reduced by discharging the grease from the cylinder 52, contracting the piston rod 51, and pulling back the idler 13 to the sprocket side by the tensional force applied to the crawler belt 17.

An energizing force of the recoil spring 53 is always applied to the idler 13. Accordingly, when the idler 13 is exposed to a great impact force from an external portion and the idler 13 is displaced to the sprocket side, it is possible to absorb the impact force by the recoil spring 53.

In this case, FIG. 1 becomes confusing if leader lines are added. Accordingly, all the reference numerals used in the idler cushion apparatus 50 shown in FIG. 4 are not described. Further, since the configuration of the idler cushion apparatus 50 is not essential in the present invention, the other known configuration can be employed as far as the idler cushion apparatus can achieve a cushioning effect with respect to the slide motion of the idler.

As shown in FIGS. 3 to 5, the idler guide apparatus 20 is provided with the taper-like block 26 mounted on the track frame 11, and the idler yoke 30 mounted on a first inclined surface 26 a of the taper-like block 26. The idler yoke 30 and the taper-like block 26 can slide on the track frame 11 along a lateral direction in FIGS. 4 and 5, on the basis of the operation of the piston rod 51 of the idler cushion apparatus 50.

In the case that the piston rod 51 is only configured such as to be brought into contact with the idler yoke 30, the idler yoke 30 and the taper-like block 26 slide in a left direction in FIGS. 4 and 5 on the basis of the extension of the piston rod 51. Further, the configuration may be made such that, if an interval (not shown) is formed between the leading end of the piston rod 51 and the contact position of the idler yoke 30 by the contraction of the piston rod 51, the gap runs short by the pressing force of pressing the idler 13 in the right direction in FIGS. 4 and 5, the pressing force being applied from a crawler belt (not shown), thereby moving the recoil spring 55 in the compressing direction.

As shown in FIGS. 2 and 3, the idler guide apparatus 20 is provided with the idler yoke 30 and a pair of taper-like blocks 26 sliding on a slide plate 27 arranged on the upper surfaces of a pair of track frames 11. A pair of bearings 21 are formed in the idler yoke 30, and each of the bearings 21 rotatably bears the idler 13 via a bush 19 axially attached to an idler shaft 18.

The idler shaft 18 and each of the bearings 21 can be positioned in an idler axial direction, for example, by engaging a groove in a peripheral direction formed in the idler shaft 18 with a pair of bolts 22 inserted to the groove. Each of the bolts 22 is engaged with the bearing 21, and can be risen and set into the groove of the idler shaft 18.

Flange portions 21 a and 21 b and a hook portion 21 c protruding toward an outer side are formed in each of the bearings 21. An inclined surface 24 c inclined in a longitudinal direction of the crawler type traveling apparatus 10 is formed in lower surfaces of the flange portions 21 a and 21 b.

Rails 23 and 24 are fastened to the inclined surface 24 c formed in the lower surfaces of the flange portions 21 a and 21 b via a bolt 25. Grooves 23 a and 24 a having a second inclined surface 30 a inclined in the longitudinal direction of the crawler type traveling apparatus 10 are formed in the rails 23 and 24.

The taper-like block 26 forming the wedge-shaped first inclined surface 26 a by the first inclined surface 26 a and the bottom surface 26 b is fitted to the grooves 23 a and 24 a of the rails 23 and 24, whereby the first inclined surface 26 a can be slid along the second inclined surface 30 a. The first inclined surface 26 a and the second inclined surface 30 a form parallel inclined surfaces.

A slide plate 28 is firmly fixed to the bottom surface 26 b of the taper-like block 26, and the slide plate 28 is mounted on a slide plate 27 firmly fixed to the upper surface of the track frame 11.

A slide plate 31 is firmly fixed to an upper surface of the hook portion 21 c, and the slide plate 31 is arranged so as to face to a slide plate 33 firmly fixed to a lower surface of a bracket 32 formed in an inner side of the track frame 11. A gap S2 is formed between the slide plate 31 and the slide plate 33.

The lower surface of the bracket 32 firmly fixing the slide plate 33 is also described by an expression the lower surface of the track frame 11, in the specification, claims and abstract of the present application, regarding the bracket 32 as a part of the constituting member of the track frame 11.

Accordingly, it is possible to bear the idler yoke 30 having the bearing 21 by the taper-like block 26, and to load the idler yoke 30 having the taper-like block 26 and the idler yoke 30 on the slide plate 27 firmly fixed to the upper surface of the track frame 11.

Further, it is possible to lift the idler yoke 30 upward with respect to the track frame 11 by sliding the taper-like block 26 on the slide plate 27. Accordingly, it is possible to adjust the gap S2 between the slide plate 31 in the side of the idler yoke and the slide plate 33 in the side of the track frame.

In this case, in accordance with the present invention, the guide surface of the slide plate 27 firmly fixed to the upper surface of the track frame 11 is called as a first guide surface 34, and the guide surface of the slide plate 33 firmly fixed to the lower surface of the bracket 32 formed in the track frame 11 is called as a second guide surface 35.

As shown in FIG. 3, a guide bracket 36 is fastened to outer side surfaces of the flange portions 21 a and 21 b formed in both the right and left bearings 21 via a shim 37 by a bolt 38. A guide surface 36 a of the guide bracket 36 and a guide plate 39 firmly fixed to the side surface of the track frame 11 are adjusted by a number of the shims 37 such that a slight gap S1 exists therebetween.

When an external force in an axial direction of the idler shaft 18 is applied to the idler 13, the guide surface 36 a of the guide bracket 36 is brought into contact with the guide plate 39, thereby preventing the idler 13 from moving in the idler axial direction.

Actuating means for adjusting the position of the taper-like block 26 is constituted by an adjusting bolt 41 for pressing the taper-like block 26 in a left direction in FIG. 2 and a spring 43 for energizing the taper-like block 26 to the adjusting bolt, as shown in FIG. 2.

The adjusting bolt 41 is engaged with a screw hole 23 c pieced in a projection portion 23 b of the rail 23, and a protruding amount of the adjusting bolt 41 from the projection portion 23 b to the taper-like block 26 can be fixed by a lock nut 42.

The spring 43 is arranged between the bearing 21 and the taper-like block 26. It is possible to inhibit the taper-like block 26 from executing an unnecessary movement in a left direction in FIG. 2 by an energizing force of the spring 43. In other words, a play of the taper-like block 26 can be restricted. In addition, when loosening the adjusting bolt 41 so as to move the adjusting bolt 41 from a state in FIG. 5 to a state in FIG. 4, that is, in a direction moving apart from the taper-like block 26, the taper-like block 26 can follow the movement of the adjusting bolt 41 on the basis of the energizing force of the spring 43.

Actuating means for sliding the taper-like block 26 on the slide plate 27 is configured by the adjusting bolt 41 and the spring 43.

When the slide plate 31 and the slide plate 33, and the slide plate 27 and the slide plate 28 are worn away from the state shown in FIG. 4, the gap S2 between the slide plate 31 in the side of the idler yoke and the slide plate 33 in the side of the track frame is expanded.

At this time, the taper-like block 26 is slid in the left direction in FIG. 4 by manually rotating the adjusting bolt 41 so as to screw in the direction of the thread hole 23 c as shown in FIG. 5. In accordance that the taper-like block 26 slides in the left direction in FIG. 4, the idler yoke 30 moves to the upper side in FIG. 4.

Then, it is possible to adjust a gap S2′ between the slide plate 31 in the side of the idler yoke 30 and the slide plate 33 in the side of the track frame in a reduced state as shown in FIG. 5. When the gap S2′ between the slide plate 31 and the slide plate 33 comes to an optimum gap, a position of the adjusting bolt 41 is fixed by rotating the lock nut 42.

At this time, the protruding amount of the piston rod 51 of the idler cushion apparatus 50 is not changed, and the pressing force to the idler yoke 30 by the idler cushion apparatus 50 comes to a fixed state.

The description is given of the configuration in which the adjusting bolt 41 is manually rotated, but, the adjusting bolt 41 may be rotated via a drive motor or the like. Further, it is possible to control a rotational amount of the adjusting bolt 41 by using a control motor which can control a rotational amount as the drive motor, and it is possible to adjust the gap S2 between the slide plate 31 in the side of the idler yoke and the slide plate 33 in the side of the track frame by means of a remote control.

Second Embodiment

FIG. 6 shows another embodiment according to the present invention. In the first embodiment, the description is given of the actuating means constituted by the adjusting bolt 41 and the spring 43, as the actuating means for sliding the taper-like block 26. On the contrary, actuating means in a second embodiment of the invention employs actuating means using a grease cylinder 44 in place of the adjusting bolt 41.

The other configurations than the configuration using the grease cylinder 44 as the actuating means in the second embodiment are the same as the configurations in the first embodiment. Accordingly, in the description of the second embodiment, the description of the same configurations as those of the first embodiment will be omitted by using the same reference numerals of the same configurations as those of the first embodiment. A description will be given below mainly of the different configurations from the first embodiment.

In FIG. 6, the grease cylinder 44 serving as the actuating means is attached to the bearing 21 via a bracket 48. A leading end portion of a piston 45 is brought into contact with the taper-like block 26. The taper-like block 26 can slide in a left direction in FIG. 6 on the slide plate 27 by an extension of the piston 45.

The taper-like block 26 is inhibited from an unnecessary movement, that is, a play in the left direction in FIG. 6, by the spring 43. Further, when the piston 45 is contracted, the taper-like block 26 can be moved in a right direction in FIG. 6 following to the contracting motion of the piston 45 by means of an energizing force of the spring 43.

The piston 45 can be expanded by loosening a valve screw 47 of the grease cylinder 44 and injecting a grease in a grease nipple 46. Further, the piston 45 can be contracted by taking out the grease from the grease nipple 46.

Using the grease cylinder 44 makes it possible to increase the pressing force sliding the taper-like block 26, whereby the slide of the taper-like block 26 can be smoothly executed. Further, a hydraulic cylinder can be employed in place of the grease cylinder 44. By remote controlling the hydraulic cylinder, it is possible to adjust the gap S2 between the slide plate 31 in the side of the idler yoke and the slide plate 33 in the side of the track frame by a remote control.

In accordance with the present invention, even in the working field of the vehicle provided with the crawler type traveling apparatus, it is possible to easily adjust the gap S2 between the slide plate 31 in the side of the idler yoke and the slide plate 33 in the side of the track frame. Accordingly, it is possible to easily prevent the play between the idler shaft and the bearing, and easily reduce the traveling noise in the working field.

Moreover, in order to adjust the gap mentioned above, it is not necessary to detach the idler so as to execute a welding repair of the wear part and a replacement of the wear part as is different from the conventional one. Accordingly, it is possible to easily execute the adjusting work for adjusting the gap even in the working field in which any equipment for detaching the idler having a great mass in the conventional configuration.

Accordingly, in the working field of the vehicle provided with the crawler type traveling apparatus, the gap can be adjusted all the time when it is necessary to adjust the gap.

INDUSTRIAL APPLICABILITY

In accordance with the present invention, the technique of the present invention can be applied to a guide apparatus in which a slide member arranged between a pair of guide surfaces is brought into slide contact with one guide surface, and a gap is provided with respect to the other guide surface, wherein it is necessary to adjust the gap mentioned above. 

1. An idler guide apparatus having a first guide surface and a second guide surface which are respectively provided in an upper surface and a lower surface of a track frame and form slide surfaces in a radial direction of an idler in a crawler type traveling apparatus, characterized in that an idler yoke rotatably bearing the idler is mounted on the first guide surface provided in the upper surface of the track frame, and an adjusting mechanism for adjusting a gap between the second guide surface provided in the lower surface of the track frame and a guide plate of the idler yoke facing to the second guide surface is formed in the idler yoke.
 2. The idler guide apparatus according to claim 1, wherein the idler yoke is constituted by an idler yoke comprising a taper-like block having a first inclined surface, and a second inclined surface slidably contacted with the first inclined surface and parallel to the first inclined surface, and the adjusting mechanism is constituted by a mechanism which slides the taper-like block on the first guide surface and displaces the idler yoke in a perpendicular direction to the track frame.
 3. The idler guide apparatus according to claim 2, wherein the adjusting mechanism comprises actuating means for sliding the taper-like block on the first guide surface.
 4. The idler guide apparatus according to claim 3, wherein the actuating means presses the taper-like block in a downward inclining direction side of the first guide surface, and comprises an adjusting bolt engaged with the idler yoke and a spring for energizing the taper-like block to the adjusting bolt.
 5. The idler guide apparatus according to claim 3, wherein the actuating means presses the taper-like block in a downward inclining direction side of the first guide surface, and comprises a cylinder apparatus arranged in the idler yoke and a spring for energizing the taper-like block to the cylinder apparatus. 